• Mass Spectrometry Letters
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• 제10권2호
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• pp.50-55
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• 2019

The fragmentation statistics of ion trap CID (Collision-Induced Dissociation) spectra using 87,661 tandem mass spectra of doubly charged tryptic peptides are analyzed here. In contrast to the usual method of using intensity information, the frequency of occurrence of fragment ions, with respect to the position of the cleavage site and the residues at these sites is studied in this paper. The analysis shows that the frequency of occurrence of fragment ion peaks is more towards the middle of the peptide than its ends. It was noted that amino acid with an aromatic and basic side chain at N- & C- terminal end of the peptide stimulates more peaks at the lower end of the spectrum. The residue pair effect was shown when the amide bond occurs between acidic and basic residues. The fragmentation at these sites (D/E-H/R/K) stimulates the generation of the y-ion peak. Also, the cleavage site H-H/R/K stimulates the generation of b-ions. K-P environment in the peptide sequence has more tendency to generate y-ions than b-ions. Statistical analysis helps in the visualization of the CID fragmentation pattern. Cleavage pattern along the length of the peptide and the residue pair effects, enhance the knowledge of fragmentation behavior, which is useful for the better interpretation of tandem mass spectra.

• Journal of Plant Biology
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• 제17권4호
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• pp.38-44
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• 1974

The distribution of corticolous lichens had been investigated in the suburb of Seoul in which factories are located densely and Yeosu which located near sea and very few factories are seen in the neighbour. Ten cm point frame was located at random on the trunk of Pinus densiflora, Quercus serrata and Carpinus Tschonoskii from bottom at 0.5m intervals to 8m height of each trees. The occurrence of each species was represented as a percentage of total quadrat frequency and of density. The density of the corticolous lichens was 2.8%, 6.9% and 7.6% at Dongkooneung, Kongneung and Kwangneung apart 15km, 25km and 32km from center of Seoul respectively. In Yeosu district, the occurrence is fairly different from that of Seoul: it is 34.8% and 34.9% at Odongdo and Hoamsan which located within 3km and 5km from the center of Yeosu. The greater frequency of the lichens on the trunk was found at 1~2m height of trees and they were found mostly on the trunk faced south. However, Pertusaria trochophora species occurred more often on the trunk faced east, Graphis scripta on east and north, Parmelia pertusa and Parmelia tinctorum on west side of trunk. Parmelia pertusa increased with increasing height of trees, but Calicium trabinellum and Anzia japonica decreased. Cetraria collata occurred mostly on the middle of above two species. SO2 concentration in the air of Seoul was high enough to eliminate the lichens except Pertusaria trochophora and Graphis scripta.

• 한국안전학회지
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• 제32권1호
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• pp.75-81
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• 2017

A series of laboratory experiments has been performed in order to investigate the behavior of water-air two-phase flow in a horizontal pipe. A conductivity meter has been applied to detect the irregular alternation of air at the specific points in flows. The experimental condition has been established according to the water and air flowrates. Passing time, which is the time length for a measuring probe to pass through the entire length of a specific bubble, has been defined to evaluate the size of bubbles in the flow. Passing length, which can be considered as the equivalent value to bubble size and determined from the product of passing time and cross-sectional averaged velocity, and its corresponding occurrence frequency have been analyzed to classify the air flow patterns according to the condition of air and water fluxes. From the result, the dependancy of flow patterns on the variation of air-water flux ratio has been investigated and the existence of thresholds also checked for classifying the behavior of air in the flow.

• 대한전기학회논문지:시스템및제어부문D
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• 제54권10호
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• pp.615-619
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• 2005

Token coherence protocol has many good reasons against snooping/directory-based protocol in terms of latency, bandwidth, and complexity. Token counting easily maintains correctness of the protocol without global ordering of request which is basis of other dominant cache coherence protocols. But this lack of global ordering causes starvation which is not happening in snooping/directory-based protocols. Token coherence protocol solves this problem by providing an emergency mechanism called persistent request. It enforces other processors in the competition (or accessing same shared memory block, to give up their tokens to feed a starving processor. However, as the number of processors grows in a system, the frequency of starvation occurrence increases. In other words, the situation where persistent request occurs becomes too frequent to be emergent. As the frequency of persistent requests increases, not only the cost of each persistent matters since it is based on broadcasting to all processors, but also the increased traffic of persistent requests will saturate the bandwidth of multiprocessor interconnection network. This paper proposes a new request mechanism that defines order of requests to reduce occurrence of persistent requests. This ordering mechanism has been designed to be decentralized since centralized mechanism in both snooping-based protocol and directory-based protocol is one of primary reasons why token coherence protocol has advantage in terms of latency and bandwidth against these two dominant Protocols.

• Journal of Radiation Protection and Research
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• 제10권1호
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• pp.29-40
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• 1985

The objectives of present study is to investigate genetic damage of radiation in mammalian male germ cell and. to establish available screening method for determining genetic hazard by radiation. Several methods were employed to measure the genetic damage of radiation as follows: Sperm head counts, frequency occurrence of sperm with abnormal head shape, fertility, activity of LDH-X, and the induction of unscheduled DNA synthesis (U.D.S.) in male mouse were performed with the passing of time after irradiation by making use of the sequence of event that occurs during spermatogenesis. Sperm head counts and activity of LDH-X in testes were gradually reduced by increased radiation dose and with the passing of the time after irradiation. Frequency occurrence of sperm with abnormal head shape, sterile period, and the induction of unscheduled DNA synthesis were increased by increased radiation dose. It is suggested that since germ cell is a direct reflection of genetic complement, the use of male germ cell is rapid and convenient method for measuring genetic damage by radiation.

• 한국안전학회지
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• 제27권1호
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• pp.32-43
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• 2012

"low and old age trend" is a big social national problem in korea but also in foreign countries. The Government pursues a policy for aged people to take part in construction site as labours. Low childbirth and avoidance of 3D work kinds lead to exposure of aged workers to industry work places. According to korea department of labour, it is expected that 18% of total economic activity people in 2008 to 27.2% in 2018 be increased with age of more than 55 old years. Therefore, It is needed that more countermeasures for old workers should be taken for safer work conditions. This old workers with more than 55 old years contain major portion of accident occurrence in construction industry. It is found that accident rate in construction industry can be decreased if appropriate technical safety training is provided to them who wish to work at construction sites. Statistic analysis such as frequency, cross, logistic regression using program package SPSS 13.0 has been made after collecting questionnaire survey of more than 330 workers at construction sites.

• Structural Engineering and Mechanics
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• 제24권4호
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• pp.493-508
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• 2006

Vibration mode localization and frequency loci veering in disordered coupled beam system are studied in this paper using finite element analysis. Two beams coupled with transverse and rotational springs are examined. Small disorders in the physical parameters such as Young's modulus, mass density or span length of the substructure are introduced in the investigation of the mode localization and frequency loci veering phenomena. The effect of disorder in the elastic support on the mode localization phenomenon is also discussed. It is found that an asymmetric disorder in the weakly coupled system will lead to the occurrence of mode localization and frequency loci phenomena.

• 대기
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• 제21권4호
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• pp.361-371
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• 2011

In this study, characteristics and trends of tropical night (TN) are investigated by using the KMA 14 observation data for the recent 50 years (1958-2007) over South Korea. The TN is defined as a day with a daily minimum temperature exceeds the absolute threshold temperature ($25^{\circ}C$), and the relative deviation from normal temperature, 95th percentile of all observed daily minimum temperature. Although the spatial distribution of TN occurrence depends on the choice of the definitions, the frequency of TN shows strong spatial and interannual variations with the minimum at high land area (Chupungnyeong and wet years) and maximum at southern coastal area and large city area (Jeju, Busan, Seoul, Daegu). Most of TN occurs in August (56%) and July (41%), and the duration date of TN is proportional to the frequency of TN without regard to the definition method. In general, increasing trends are found in the TN time series without regard to the analysis method, but the trends are clearly depending on the analysis period and geographic locations. Decreasing trends are prominent during the most of analysis period, especially until the mid of 1990, whereas strong increasing trends are found during recent 30 years (1988-2007), especially at Jeju, Ulsan, Daegu and Pohang. Also the severity of TN is significantly increased in recent years.

• 수산해양기술연구
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• 제55권2호
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• pp.145-151
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• 2019

The coastal composite fishery has the highest rate of around 30.0% in registered fishing vessels of Korea for the last three years. The risk analysis for the fisher's safety of coastal composite fishing vessels was conducted to serve as a basic data for improving the healthy and safe working environment of fisher using fisher's occupational accidents of the national federation of fisheries cooperatives (NFFC) from 2016 to 2018 (n = 1,105). As a result, the occupational accident occurrence rate of coastal composite fishery was 3.76% in all industries, 7.8 times the rate of that. In addition, death and missing rate was found to have a serious level management to 10.10‱. Among the accidents, 76.0% occurred at sea. The slipping, others and contact with machinery or fishing gear occurred more frequently in order in the frequency of accident occurrence pattern. In the risk assessment using frequency and severity, slipping, contact with machinery and others showed high risk during fishing. The results are expected to contribute to identification and assessment of safety hazard occurred in coastal composite fishing vessels.

• 한국경영과학회지
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• 제40권4호
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• pp.49-63
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• 2015

Keyword indexed in multidisciplinary journals show trends about science and technology innovation. Nature and Science were selected as multidisciplinary journals for our analysis. In order to reduce the effect of plurality of keyword, stemming algorithm were implemented. After this process, we fitted growth curve of keyword (stem) following bass model, which is a well-known model in diffusion process. Bass model is useful for expressing growth pattern by assuming innovative and imitative activities in innovation spreading. In addition, we construct keyword co-occurrence network and calculate network measures such as centrality indices and local clustering coefficient. Based on network metrics and yearly frequency of keyword, time series analysis was conducted for obtaining statistical causality between these measures. For some cases, local clustering coefficient seems to Granger-cause yearly frequency of keyword. We expect that local clustering coefficient could be a supportive indicator of emerging science and technology.